1. Technical Field
The present invention relates to a power control device, and more particularly, to a standby power control unit which uses a micro-process unit or a transformation unit to detect the boot/shut down state of a computer, and uses a power control unit to cut off the standby power of the computer and the peripheral devices thereof for saving electrical power after the computer is shut down.
2. Description of Related Art
Basically, a conventional computer consists of: a motherboard, a hard disk, a processor, a graphic card, and a memory. In order to promote the conveniences for user to access data, the conventional computers equip with a soft disk, a card reader, and a CD-ROM. Besides, for increasing the conveniences of the living and the work of people, there are many peripheral devices of the conventional computer released by computer suppliers, such as: printer, displayer, modem, speaker, TV-box, scanner, etc.
The conventional computers are booted and shut down by users, similarly, the peripheral devices as above-mentioned are turned on/off by the users as well. However, after the computer being shut down, the users often forget to turn off the power switches of the peripheral devices so as to waste power, moreover, energy will loose a lot while in a hot season.
For improving the situations of wasting the power, there are various power control devices and methods provided. Referring to FIG. 1, which illustrates a framework of a system for power control in a Universal Serial Bus (USB). As shown in FIG. 1, a Bus powered hub 1′ is used to be a power supplier of a plurality of peripheral devices 3′, so that a computer 2′ can easily control the ON/OFF state of the peripheral devices 3′ for achieving the purpose of saving power. Besides, referring to FIG. 2, which shows a framework of a power control device of controlling power of peripheral devices of a computer system using a universal serial bus hub. As shown in FIG. 2, a computer 1a outputs a state signal of a monitor 4a to a USB hub 10a, wherein the monitor 4a is connected to the computer 1a. The USB hub 10a includes a micro-process unit, which can control the power switch of the monitor 4a according to the state signal outputted by the computer 1a, so that the power dissipation of the monitor 4a is reduced to the lowest level, the power is saved.
As aforesaid, the system for the power control in the universal serial bus (USB) and the power control device of controlling the power of the peripheral devices of the computer system using the universal serial bus hub, which have simple design and best functions but still have defects and shortcomings listed as following:                1. In the system for the power control of the universal serial bus (USB), the Bus powered hub is a main power controller for the plurality of peripheral devices, however, the Bus powered hub obtains the power from the computer, so that the Bus powered hub can't control the ON/OFF state of the power of the computer;        2. In the power control device of controlling power of peripheral devices of the computer system using the universal serial bus hub, the USB hub can only control the power of the monitor for reducing the power dissipation of the monitor to the lowest level, but the USB hub can't save the power of other computer peripheral devices.        
Accordingly, in view of the shortcomings of the conventional power control systems and devices, the inventor of the present invention has made great efforts to make improvement thereof and finally provides a standby power control device.